1. Field of the Invention
The present invention relates generally to analyzing software performance, and more particularly, to a system, method, and program for graphically presenting code execution data in order to quickly identify of areas of code which may represent opportunities for optimization.
2. Related Art
Performance is an important aspect of software design. If an application does not perform well, users will not likely want to use that application. Performance is a subjective term referring to the general way in which something operates. Performance may include how efficiently system resources (e.g., CPU, memory, and hard disk drive) are used. There are aspects of performance, including but not limited to speed, memory footprint, memory turnover, memory usage, file-system usage, etc., that can be measured. Improving on these measurements increases the efficiency of the software.
Software programs can have poor performance due to any of a number of different problems. The reason for poor performance of a particular software program is not always apparent. In particular, large-scale software can be extremely complex, with multiple layers and many modules, such that implementation details (those causing performance problems) are often hidden across the layers and modules.
In connection with analyzing software performance, software programs can be “sampled” at runtime. The samples may provide a statistical representation of how much CPU time is spent in each function. Samples may be taken continuously, for example, during execution of a program, from a specified start time to a specified end time. Samples may also be taken periodically, for example, at specified time intervals (time-based sampling). When a sample is taken, the program's stack backtrace and other information can be recorded, and entered into a “trace table.” A trace table may have many thousands of such entries, depending on how many samples were taken. Analyzing sizeable trace tables for complex software programs can be very difficult and time-consuming.